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1. Field of the Invention
The present invention relates to apparatus for liquid cooling by conduction of specific computer components mounted within a housing for a computer in order to reduce the operating temperature of such components.
2. Description of the Related Art
As certain components for computers, such as microprocessors or hard disk drives become more powerful and complex, while maintaining compact size, more effective thermal management becomes necessary in order to maintain desirable operating temperatures. It is well known that according to the Arrhenius equation, there is an exponential increase in failure rates with incremental increases in operating temperatures. For example, assuming a 1.0 eV activation energy, the failure rate doubles for every 10xc2x0 rise in operating temperature. Therefore, increase in power of computer chips such as the Pentium(copyright) requires more effective heat management techniques to prevent undesirable rises in operating temperatures.
It is known to apply air-cooled fin modules directly to electronic components in order to dissipate heat through conduction by use of finned heat exchangers and convection with such heat exchangers being cooled by air flow. For example, Intel""s 486 microprocessor was cooled by a conformal finned heat exchanger, and Intel""s Pentium(copyright) chip has been cooled by finned type heat exchangers which have surface area extending beyond the actual contact surface area of the Pentium(copyright), sometimes known as extended surface heat exchangers. The operating power of certain components such as newer versions of Pentium(copyright) chips of Intel has reached levels which require high volumes of forced ambient air to dissipate generated heat; however, forced air to cool finned modules have limitations in that there may be an upper limit to volumetric flow of cooling air due to noise or other factors such as increased power requirements.
Cooling systems other than finned surface area exchangers are currently known in the prior art. For examples Peltier coolers and heat pipes are known. But, the potential height of Peltier coolers as well as the requirement for extra cooling load due to inherent inefficiencies reduce the probability for successful application to high heat load components. And, heat pipes have heat transfer capacity limitations due primarily to losses in realizing connection to hot and cold thermodynamic reservoirs, but also due to limitations of heat transport due to internal design limits.
It is also known to use cooling plates for circulating liquid coolant, which plates are mounted in contact with various power modules such as transistors, diodes and rectifiers. For example, the EGandG Components Division of Wakefield Engineering of Wakefield, Massachusetts manufacturers sheet plates which are bent to conform, that is, crimped about cooling tubes and water-cooled solid copper blocks designed to cool pressure mounted rectifiers and SCR""s dissipating up to 2 kw per device. The Wakefield cooled plates have several disadvantages in that there is significant thermal resistance across the interface between the copper tube and the aluminum plate, and in that crimping of tubes in such a manner has been found to lead to variations in cooling of up to 50 percent.
A number of prior art patents are directed to the use of liquid coolant to cool electronic components, particularly in large main frame type computers. U.S. Pat. No. 5,159,529 utilizes a plastic internal cooling core having mounted to it one or more cooling plates of copper to receive various electronic components. However, the attachment of cooling plates of copper to a plastic core may cause possible leak problems due to material incompatibility. U.S. Pat. No. 5,144,532 discloses the use of two oppositely positioned liquid cooling plates which are in contact with printed circuits positioned on opposite sides of a multi-layer printed circuit board. U.S. Pat. No. 4,748,495 discloses a liquid cooling module for a plurality of integrated circuit chips arrayed in uneven height wherein cooling fluid is routed either through a group of heat sinks or independently through each of a number of heat sinks. And, U.S. Pat. No. 4,758,926 discloses utilizing heat sinks having microchannels to receive cooling fluid for cooling chips.
While the prior art encompasses the general use of cooling fluid or coolant to cool electronic components, there remains a need to develop a high capacity cooling system for mounting within computer housings for desktop and server size computers where the cooling system is in direct contact with the most powerful and highest heat generating electronic components, such as more recent and more powerful versions of the Pentium(copyright) processor and hard disk drives. It is accordingly an object of this invention to provide a cooling system specifically directed to such components.
In accordance with various embodiments of this invention, apparatus is provided for transferring heat from high heat generating electronic components such as advanced, high powered computer chips and hard disk drives. In one embodiment, such apparatus includes a generally rectangular chassis having a plurality of components including a mother board, with a processor chip being mounted in one of the processor slots on the mother board. A heat exchange assembly includes a power supply mounted in one corner of the chassis having a fan mounted adjacent to the power supply. The heat exchange assembly is provided for dissipating heat generated by the chip including an air to liquid heat exchanger mounted on the chassis adjacent to the fan, a pump mounted on the chassis at a convenient point and a heat transfer plate having a configuration substantially identical to the bottom surface of the high heat generating chip. The heat transfer plate is connected to the air side heat exchanger and pump by suitable tubing lines so that a liquid coolant can be transferred to the heat transfer plate in order to remove heat from the high heat generating chip, with the heated coolant being cooled in the air side heat exchanger and returned by the pump to the heat transfer plate in a continues fashion.
In another embodiment of this invention, apparatus is provided for cooling an operating hard disk drive, including a generally U-shaped heat exchange clip for resilient mounting onto the sides of the hard disk drive container. The U-shaped clip has external liquid coolant flow loops attached on the outside of the clip in order to transfer heat from the hard disk drive. In another embodiment of cooling for an individual hard disk drive, apparatus includes a generally rectangular heat transfer plate having substantially the same dimensions as a surface of a hard disk container for transferring heat from such container.
And, further apparatus is provided for transferring heat from a vertical array or stack of hard disk drive units. Such apparatus includes one or more panels mounted between adjacent, vertically positioned hard disk drive units in order to remove heat from adjacent units simultaneously.
This summary of the invention is intended as a general description of the attributes of this invention, which will now be described in more detail in the detailed description, with the claims to follow setting forth the subject matter sought to be patented.